Chemoelectrical Gas Sensors of Metal Oxides with and Without Metal Catalysts

摘要

The interest for gas sensors is uprising due to the increased demand for many applications such as: Security, Environment, Industry, Medicine etc. Therefore, the development of new, cheap, easy to prepare, simple, low energy consuming and reliable sensors have become of great significance. A category of gas sensors with these characteristics is the metal oxide chemoelectrical sensors that are the most common ones used today. The sensing properties of these sensors depend mainly on the surface properties such as roughness, porosity, crystallinity etc. that are strongly depended on the preparation method. Moreover, the addition of metal nanoparticles and especially nanoparticles of noble metals with catalytic properties differentiate (mostly improve) the sensing efficiency. In this work we used the PLD technique to prepare thin films of Cu_xO (1 < x < 2) and surface decorated some of them with gold nanoparticles to be used as sensors. These sensors consisted of the sensing thin film on the surface of a quartz tube surrounding a ceramic heater with low thermal capacity. The films are characterized by AFM and SEM techniques. A significant response to several concentrations of the hydrogen and acetone at relative low temperatures was demonstrated.